Elevator system

ABSTRACT

An elevator system including an elevator car, counterweight, hoisting ropes interconnecting the elevator car and counterweight, and a drive for moving the car and counterweight in guided paths. A compensation system is provided which includes at least one metallic strip disposed between the elevator car and counterweight.

United States Patent 1191 Suozzo 1 May 13, 1975 [54] ELEVATOR SYSTEM1,944,772 1/1934 White 187/22 2.537,075 1/1951 Margles 187/22 [75]Inventor? Hackensack 3,653,467 4/1972 Showalter 187/22 [73] Assignee:Westinghouse Electric Corporation,

Pittsburgh, Pa. Primary Examiner-Evon C. Blunk Assislant Examiner-JamesL. Rowland [22] Filed June 1973 Attorney, Agent, or Firm-D. R. Lackey[21] Appl. No.: 366,234

[57] ABSTRACT [52] U.S. C1 187/22; 187/94 l d 51 Int. Cl. B66b 11/08 fYstem "9 mg [58] Field of Search l87/2022, wegm ropes P h 816mm 187/2638 94 and counterweight, and a drive for moving the car andcounterweight in guided paths. A compensation sys- [561 iii? 11 1525122:11:11:32,353?$32112? UNITED STATES PATENTS g 975,790 11/1910Pearson 187/20 1,132,769 3/1915 Gale 187/22 5 Claims, 3 Drawing Figuresr T" 64 I ELEVATOR SYSTEM BACKGROUND OF THE INVENTION 1. Field of theInvention:

The invention relates in general to elevator systems, and morespecifically to compensation systems for elevators.

2. Description of the Prior Art:

Elevator systems of the traction type conventionally employ compensationfor the weight of the hoist ropes where the travel exceeds about 100feet. This minimizes the unbalance between the car and counterweight asthe car changes its position in the hoistway, providing more uniformtorque requirements and assisting landing accuracy. Chains areconventionally used for compensation for elevators which operate at atravel rate of less than about 500 feet per minute, while strandedcables are used above a rate of 500 feet per minute. This changeoverpoint between chains and roping for compensation is dictated primarilyby acoustic noise, as chain compensation becomes objectionably noisyabove about a 500 feet per minute travel rate.

While compensation in the form of a plurality of stranded cables isgenerally satisfactory, a problem may arise on windy days in high speedelevator systems which operate above about 1100 or 1200 feet per minute.When the wind is blowing outside a tall building, the difference inpressure between the bottom and top thereof can be quite substantial,resulting in wind velocities in the hatchway of an elevator systeminstalled therein which may cause the compensating cables to sway. Whenthis occurs, there is a possibility that the cables may become tangledand damaged.

SUMMARY OF THE INVENTION Briefly the present invention is a new andimproved elevator system of the electric traction type, which utilizes anew and improved compensation system. Instead of using cables in thecompensation system, as taught by the prior art, metallic strip is usedto interconnect the bottoms of the elevator and counterweight. A singlemetallic strip formed of a suitable material, such as steel, may beselected to provide the total compensation required for a specificinstallation. Alternatively, a metallic strip of a suiutable standardsize may be used, such as metallic strip having a width dimension of 4.5inches and a thickness of 1/32 inch. A steel strip of these dimensionsweighs about 0.57 pound per foot,

.which is approximately the same as the /8 inch diameter cableconventionally used for compensation. The desired compensation andweight per foot for each application is then achieved by selecting therequired number of metallic strips and superposing or stacking themtogether.

A compensation system using metallic strip is not subject to tanglingand damage due to wind in the hatchway as the strips will already be inpreparranged contact with one another. Further, the metallic strip islower in initial cost than the cables conventionally used, the metallicstrip is easier to install in the field than the conventional cables,the metallic strip improves the riding quality as it eliminatesvibration due to compensating cables, and the metallic strip has alonger useful operating life than the compensating cables of the priorart.

While a conventional compensator employing a heavy cast iron sheave maybe used to guide and tension the metallic strip compensation, themetallic strip compensation permits a new and improved compensator to beused. Instead of a heavy cast iron sheave, a plurality of small rollersmay be used to guide the metallic strip, with the frame on which therollers are mounted being pivotally biased by means such as a spring toprovide the desired tension in the strip. This arrangement substantiallyreduces the mass to be accelerated by the elevator drive machine, i.e.,drive motor and direct current voltage source, and thus reduces driverequirements. The placement of the rollers on their support frame may bemade adjustable to suit the distance from the car to the counterweightfor each application, providing vertical compensation on the car andcounterweight without a transverse component. This adjustment feature isnot available with cast iron sheaves which are manufactured to only afew predetermined different diameters.

BRIEF DESCRIPTION OF THE DRAWINGS The invention may be betterunderstood, and further advantages and uses thereof more readilyapparent, when considered in view of the following detailed descriptionof exemplary embodiments, taken with the accompanying drawings, inwhich:

FIG. 1 is a perspective view of an elevator system constructed accordingto the teachings of the invention; and

FIGS. 2 and 3 are side and end elevations, respectively, of an elevatorsystem constructed according to another embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings,and FIG. 1 in particular, there is shown an electric elevator system 10of the traction type constructed according to the teachings of theinvention. Elevator system 10 includes an elevator car 12 mounted forguided movement in a hoistway 14 of a building 15 having a plurality offloors to be served by the elevator car. An elevator drive motor 16,which may be disposed in a penthouse on the building 15, drives atraction sheave 18 via a drive shaft 20, and, if required, a deflectionsheave 22 may be used in combination with the traction sheave 18 toobtain the required spacing between the elevator car 12 and acounterweight 24.

A plurality of hoisting ropes or cables 26 interconnect the elevator car12 with the counterweight 24. The hoisting ropes 26 extend from the car12 about the traction and idler sheaves l8 and 22, respectively, usingthe half wrap shown, or a full wrap, and then to the counterweight 24.The hoisting ropes 26 may be connected to the overhead channels of theelevator car and counterweight, if the roping is l to 1 as illustrated,or the hoisting roping may be reeved about a sheave carried by the carand/or counterweight, if either is roped 2 to l, in which event thehoisting roping would be dead ended above the travel paths of theelevator car and/or counterweight. As illustrated, the elevator car 12includes a cab 28 mounted in a sling 30, with the cables 26 beingconnected to the top channel 32 of the sling 30.

'Conventionally, a plurality of compensating cables, such as /8 inchdiameter wire ropes, would be connected to the bottom channel 34 of thecar sling 30, they would run about a weighted compensator in the pit andthen be fastened to the bottom channel of the counterweight 24. FIG. 1illustrates a new and improved compensation system constructed accordingto the teachings of the invention which possesses many advantages overthe prior art compensating roping arrangement, with a simpler, lesscostly, longer life structure.

More specifically, the compensation system shown in FIG. 1 includes ametallic strip 40 as the compensating means, instead of wire rope.Metallic strip is defined as a sheet of metal, such as steel, having alength dimension L much longer than its width dimension W, and with thewidth dimension W being many times its thickness dimension T. The strip40 is connected to the car 12, such as to the bottom channel 34 of thesling 30, it runs about a weighted compensator 42 disposed in the pit,and is then connected to the bottom channel of the counterweight 24.

The thickness dimension I of the metallic strip 40 is selected on thebasis of providing the necessary flexibility to run about the weightedcompensator 42, and

- strength to withstand the tension applied to the strip 40 by thecompensator. The width dimension W is se lected to provide apredetermined weight per foot of length, and may be selected to providethe total compensation required for the car, thus, requiring one strip;or, the weight per foot of a single strip may be selected to be lessthan the total compensation required, with a plurality of strips thenbeing necessary to achieve the compensation required. For example, eachstrip may be selected to have the same weight per foot as theconventional /8 inch diameter wire rope used in prior art compensationsystems, which for 1/32 inch thick steel strip would be about 4.5 to 5inches. If the strip is selected to have the same weight per foot as theprior art compensation cable, the number of strips required forcompensating a specific application would then be the same as the numberof ropes which would have ordinarily been used for this application.However, it will be appreciated that the weight per foot of the strip 40may be more or less than a inch diameter wire rope, requiring fewer ormore metallic strips, respectively, than the number of ropes in a priorart compensation system for a similar application. Also, as hereinbeforestated, the metallic strip dimensions may be selected such that only asingle strip need be used, if desired.

If a plurality of strips are used to achieve the required compensation,instead of the metallic strips being separated, as are the ropes in aconventional rope compensating system, they are superposed with themajor surface of one metallic strip superposed directly over andcontacting the major surface of the next adjacent strip. The pluralityof superposed metallic strips thus function as a unit and there is nopossibility of tangling due to wind in the hoistway on windy days. Thesteel strip required to provide a predetermined weight per foot is lesscostly than wire rope for the same weight per foot for compensation.Metallic strip may be selected which has a longer operating life thanwire rope, as already proven by the long life achieved by the steelstrip or tape used in the drive for the electromechanical floor selectorused in elevator systems. The metallic strip is also easier to connectto the elevator car and counterweight, than a plurality of cables,reducing field labor costs, and it doesnt transmit the vibrations to thecar 4 which a plurality of compensating cables do, improving the ridequality.

The compensator 42 shown in FIG. 1 is illustrated in combination withtheconventional weighted compensator which uses a heavy cast iron sheave 44mounted for rotation in a frame 46. The frame 46 is allowed limited upand down guided movement to accommodate elastic and permanent stretch ofthe hoisting ropes. compensator 42 may be of the lock-down type, whichpermits limited upward movement of the frame 46 and when the limit isreached the frame 46 is locked to fixed guide rails 48 and 50, whichrails also function to guide the vertical movement of the frame 46. Thelocking of the frame to the guide rails insures similar decelerationrates for the elevator car and counterweight when one of them is stoppedrapidly, such as due to a safety or buffer stop. The locking means maybe conventional, or the locking arrangement disclosed in copendingapplication Ser. No. 347,285, filed Apr. 2, 1973, which is assigned tothe same assignee as the present application, may be used.

Instead of using the conventional weighted compensator arrangement 42shown in FIG. 1, the metallic strip compensating system disclosed hereinpermits a new and improved compensator to be used in combinationtherewith. The heavy cast iron compensator sheave 44 of the prior artmust be accelerated and decelerated by the drive 16. The rating of thedrive 16, and the rating of its source of direct current voltage must beselected accordingly. The cast iron sheave, by necessity, is constructedwith only a few different diameters. Thus, it is not always possible toprovide compensation on the car and/or counterweight without a lateralcomponent, which thus increases the wear on the guide rollers and rails.

More specifically, FIGS. 2 and 3 are side and end elevational views,respectively, of an elevator system 60 which includes an elevator car 62and counterweight 64, similar to the car and counterweight shown in FIG.1, with metallic strip 66 interconnecting the bottoms of the car andcounterweight via a new and improved compensator 70. The metallic strip66 may be a single strip, or, as shown in the magnified insert 72, itmay include a plurality of superposed strips, as desired.

The metallic strip compensation permits the compensator 70 to beconstructed using a plurality of rollers 74 disposed to contact andguide the metallic strip 66 about a predetermined loop configuration inthe pit of the hoistway. The mass of these relatively small diameterrollers is insignificant compared with the mass of the cast ironcompensator sheave 44 shown in FIG. 1, enabling the rating of the drive16 and its voltage source to be reduced accordingly. Further, themounting locations of the rollers 74 may be easily adjusted for eachelevator installation to provide vertical compensation for both the carand counterweight without a lateral force component. Rollers 74 may beprovided with a tire of resilient material, such as polyurethane, whichoperates noiselessly against the inner major surface of metallic strip66 without appreciable wear on either the strip or the tire.

The plurality of small diameter rollers 74 are mounted on a frame 76which provides the desired tension in the strip 66, while accommodatingpermanent and elastic stretch in the hoisting cables, and limiting theupward movement of the frame to tie the car and counterweight togetherduring a rapid stop of either.

Frame 76 includes a beam structure pivotally mounted at one end, such asprovided by two spaced angle members 78 and 80, each of which includesfirst and second connected portions such as the first and secondportions 82 and 84 of member 78 and the first and second portions 86 and88 of member 80. The first portions 82 and 86 each have an openingdisposed therein, which openings are aligned when the members 78 and 80are disposed in spaced parallel relation with their first portionsfacing one another and their second portions extending perpendicularlyaway from one another. A bearing assembly 90 is mounted in the alignedopenings, and a shaft member 92 is disposed through the bearing 90. Eachend of shaft 92 may be fixed to a mounting plate member, such asmounting member 94,

and the mounting plate members are secured to the counterweight guiderails, such as the counterweight guide rail 96.

The rollers 74 are mounted on spaced plate members fixed to the facingsurfaces of the first portions of members 78 and 80. Two spaced platemembers may be used, or, as illustrated in FIGS. 2 and 3, two pairs 100and 102 of spaced plate members may be used, with the dimension 104between the adjacent pairs 100 and 102 being adjusted for each elevatorduring installation to achieve a dimension 103 between the ends of theloop which provides vertical compensation for both the car andcounterweight without a lateral force component. Thus, the rollers andassociated mounting plates may be manufactured in sub-assemblies and thespacing 104 set to the proper dimension by any suitable adjusting means,such as slotted openings in portions 82 and 86 of the angles and nut andbolt combination, indicated generally at 105, which are carried by themounting plates, the bolts of which extend through the slotted openings.Thus, the loop dimension 103 may be readily adjusted.

Pair 102 of spaced plate members includes spaced mounting plates 106 and108, and pair 102 includes spaced mounting plates, such as mountingplate 110 and a similar mounting plate spaced therefrom, which is notvisible in FIGS. 2 and 3. The two pairs of spaced mounting plates areidentical, except one pair is reversed or flipped over compared with theother pair. The shafts upon which the rollers 74 are mounted, such asshaft 112, are preferably fixed to the spaced mounting plates, and therollers journaled in bearings for rotation on the shafts; or, therollers may be fixed to their associated shafts and the shafts journaledin bearings for rotation in the spaced mounting plates.

In addition to rollers 74 which direct the metallic strip 66 about aloop configuration in the pit, guide roller assemblies 116 and 118 aredisposed to contact the edges of the strips 66 to guide the strip as itenters and leaves the compensator 70. For example, guide roller assembly116 may include an angular mounting bracket or member 120 which is fixedto the upper surfaces of the spaced mounting plates members 106 and 108.The angular member 120 supports an arm 122 which is pivotally mountedthereon. The outer ends of arm 122 include guide rollers 124 and 126each having a suitable groove on its periphery for receiving an edge ofthe metallic strip 66. The rotatable arm 122 is biased in a clockwisedirection as viewed in FIG. 3, to force the guide rollers 124 and 126against the edges of strip 66. The guide rollers 124 and 126 arejournaled for rotation to rotate with the strip 66 as it moves about thecompensator The guide roller assembly 118 is of similar construction.

The tension and lock-down feature for compensator 70 is provided byupstanding cylindrical-posts 130 and 132, spiral compression springmembers 1 34 and 136, an upper spring seat 138, and nuts 140 and 142.The cylindrical posts l30 and 132 are fixed to the floor of the pit andthey extend *vertically upward through openings disposed inangles 78 and80, respectively. These openings are large enough to permit the member78 and to pivot as a unit about shaft 92 through a predetermined angle.Springs 134 and 136 are telescoped over the upstanding ends'of posts and132, respectively, with the top surfaces of the second portions 84 and88 of members 78 and 80, respectively, functioning as lower springseats. The upper spring seat 138 has openings therein for receiving theposts 130 and 132, and it is placed in position thereon to contact theupper ends of the springs 134 and 136. The nuts 140 and 142 are thendisposed on suitably threaded ends of the posts to force the spring seat138 downwardly to compress the springs 134 and 136. This biases thecompensator 70 about shaft 92 in a clockwise direction, as viewed inFIG. 2, providing the desired tension in the strip 66. The springs 134and 136 enable the compensator 70 to move up and down with changes inthe length of the hoisting ropes, but it limits upward travel of thecompensator 70 to the point where the springs 134 and 136 pipe, whichthen locks the car and counterweight together to achieve a similardeceleration rate.

In summary, there has been disclosed a new and improved elevator systemwhich precludes tangling of the compensator ropes used in the prior artby eliminating the compensating ropes and using compensation in the formof one or more metallic strips. In addition, the new compensating systemis less costly, easier to install, produces less vibration in the car,and has a longer operating life than compensating systems of the priorart.

The metallic strip compensation also enables a new and improvedcompensator to be used for tensioning and guiding the metallic strip, aswell as locking down the compensator during a rapid stop of either thecar or counterweight. The metallic strip compensation permits a seriesof small spaced rollers to be used for guiding the metallic strip abouta loop in the pit, reducing the mass which must be accelerated anddecelerated, compared with the prior art cast iron compensator sheave,and making it possible to easily achieve the desired spacing of the endsof the loop in the pit to accommodate the car and counterweight spacingfor each elevator installation. Thus, vertical compensation may easilybe provided for both the car and counterweight without a side or lateralcomponent of force.

I claim as my invention:

1. An elevator system comprising:

an elevator car;

a counterweight,

motive means mounted above said car and counterweight,

hoisting roping disposed in frictional contact with said motive meansand interconnecting said car and counterweight; said car andcounterweight being moved vertically responsive to said motive means,with said hoisting roping adding weight to said car and counterweightresponsive to their relative positions;

compensating means, said compensating means including at least onemetallic strip extending from said car to said counterweight in a loopdisposed below said car and counterweight, said at least one metallicstrip being dimensioned to provide a predetermined weight per unitlength selected to substantially reduce the weight unbalance betweensaid car and counterweight caused by said hoisting roping as therelative positions of said car and counterweight change,

tensioning means disposed below-the elevator car and counterweight fortensioning and guiding the at least one metallic loop, said tensioningmeans including support means,

a plurality of first rollers, means mounting said first rollers inspaced relation on said support means, with the at least one metallicstrip disposed to contact said first rollers,

bias means for biasing said support means to tension the at least onemetallic strip,

and a plurality of second rollers disposed to contact the edges of theat least one metallic strip and guide the at least one metallic strip asit enters and leaves the first rollers.

2. The elevator system of claim 1 wherein the compensating meansincludes a plurality of superposed metallic strips.

3.. The elevator system of claim 1 wherein the support means ispivotally mounted for rotation in a vertical plane, and the bias meansbiases the support means in a downward direction.

4. The elevator system of claim 1 wherein the tensioning means includesa plurality of rollers mounted on support means such that the rollerscontact and guide the metallic strip in a loop configuration.

5. An elevator system comprising: an elevator car; a counterweight;motive means for said car and counterweight including hoisting ropinginterconnecting said car and counterweight;

compensating means, said compensating means including at least onemetallic strip extending from said car to said counterweight in a loopdisposed below said car and counterweight, and

tensioning means disposed below the elevator car and counterweight fortensioning and guiding the at least one metallic loop, said tensioningmeans including support means, means pivotally mounting said supportmeans for rotation in a vertical plane, a plurality of first rollers,means mounting said first rollers in spaced relation on said supportmeans, with the at least one metallic strip disposed to contact saidfirst rollers, and bias means for biasing said support means in adownward direction to tension the at least one metallic strip, said biasmeans including a spring member disposed to allow a predeterminedpivotal movement of the support means, and to provide a stop beyondwhich the support means cannot pivot upwardly, to tie the elevator carand counterweight together to achieve similar rates of decelerationduring a rapid stop of either the elevator car or counterweight.

1. An elevator system comprising: an elevator car; a counterweight,motive means mounted above said car and counterweight, hoisting ropingdisposed in frictional contact with said motive means andinterconnecting said car and counterweight; said car and counterweightbeing moved vertically responsive to said motive means, with saidhoisting roping adding weight to said car and counterweight responsiveto their relative positions; compensating means, said compensating meansincluding at least one metallic strip extending from said car to saidcounterweight in a loop disposed below said car and counterweight, saidat least one metallic strip being dimensioned to provide a predeterminedweight per unit length selected to substantially reduce the weightunbalance between said car and counterweight caused by said hoistingroping as the relative positions of said car and counterweight change,tensioning means disposed below the elevator car and counterweight fortensioning and guiding the at least one metallic loop, said tensioningmeans including support means, a plurality of first rollers, meansmounting said first rollers in spaced relation on said support means,with the at least one metallic strip disposed to contact said firstrollers, bias means for biasing said support means to tension the atleast one metallic strip, and a plurality of second rollers disposed tocontact the edges of the at least one metallic strip and guide the atleast one metallic strip as it enters and leaves the first rollers. 2.The elevator system of claim 1 wherein the compensating means includes aplurality of superposed metallic strips.
 3. The elevator system of claim1 wherein the support means is pivotally mounted for rotation in avertical plane, and the bias means biases the support means in adownward direction.
 4. The elevator system of claim 1 wherein thetensioning means includes a plurality of rollers mounted on supportmeans such that the rollers contact and guide the metallic strip in aloop configuration.
 5. An elevator system comprising: an elevator car; acounterweight; motive means for said car and counterweight includinghoisting roping interconnecting said car and counterweight; compensatingmeans, said compensating means including at least one metallic stripextending from said car to said counterweight in a loop disposed belowsaid car and counterweight, and tensioning means disposed below theelevator car and counterweight for tensioning and guiding the at leastone metallic loop, said tensioning means including support means, meanspivotally mounting said support means for rotation in a vertical plane,a plurality of first rollers, means mounting said first rollers inspaced relation on said support means, with the at least one metallicstrip disposed to contact said first rollers, and bias means for biasingsaid support means in a downward direction to tension the at least onemetallic strip, said bias means including a spring member disposed toallow a predetermined pivotal movement of the support means, and toprovide a stop beyond which the support means cannot pivot upwardly, totie the elevator car and counterweight together to achieve similar raTesof deceleration during a rapid stop of either the elevator car orcounterweight.